#include "sample3-inl.h"
#include "gtest/gtest.h"

// 测试夹具: testing::Test

namespace {
// To use a test fixture, derive a class from testing::Test.
class QueueTestSmpl3 : public testing::Test {
protected:  // You should make the members protected s.t. they can be
    // accessed from sub-classes.

    // virtual void SetUp() will be called before each test is run.  You
    // should define it if you need to initialize the variables.
    // Otherwise, this can be skipped.
    void SetUp() override {      // 复写 testing::Test中的虚函数 初始化工作
        q1_.Enqueue(1);  // 插入元素
        q2_.Enqueue(2);
        q2_.Enqueue(3);
    }

    // virtual void TearDown() will be called after each test is run.
    // You should define it if there is cleanup work to do.  Otherwise,
    // you don't have to provide it.
    //
    // virtual void TearDown() {
    // }

    // A helper function that some test uses.
    static int Double(int n) {
        return 2 * n;
    }

    // A helper function for testing Queue::Map().
    void MapTester(const Queue<int> *q) {
        // Creates a new queue, where each element is twice as big as the
        // corresponding one in q.
        const Queue<int> *const new_q = q->Map(Double);

        // Verifies that the new queue has the same size as q.
        ASSERT_EQ(q->Size(), new_q->Size());

        // Verifies the relationship between the elements of the two queues.
        for (const QueueNode<int> *n1 = q->Head(), *n2 = new_q->Head();
             n1 != nullptr; n1 = n1->next(), n2 = n2->next()) {
            EXPECT_EQ(2 * n1->element(), n2->element());
        }

        delete new_q;
    }

    // Declares the variables your tests want to use.
    Queue<int> q0_;
    Queue<int> q1_;
    Queue<int> q2_;
};

// When you have a test fixture, you define a test using TEST_F
// instead of TEST.

// Tests the default c'tor.
// TEST_F 用于写测试夹具
TEST_F(QueueTestSmpl3, DefaultConstructor) {
    // You can access data in the test fixture here.
    EXPECT_EQ(0u, q0_.Size());
}

// Tests Dequeue().
TEST_F(QueueTestSmpl3, Dequeue) {
    int *n = q0_.Dequeue();
    EXPECT_TRUE(n == nullptr);

    n = q1_.Dequeue();
    ASSERT_TRUE(n != nullptr);
    EXPECT_EQ(1, *n);
    EXPECT_EQ(0u, q1_.Size());
    delete n;

    n = q2_.Dequeue();
    ASSERT_TRUE(n != nullptr);
    EXPECT_EQ(2, *n);
    EXPECT_EQ(1u, q2_.Size());
    delete n;
}

// Tests the Queue::Map() function.
TEST_F(QueueTestSmpl3, Map) {
    MapTester(&q0_);
    MapTester(&q1_);
    MapTester(&q2_);
}
}  // namespace
